This paper aims to describe a design research project which looked at how to support facility managers engage employees in behaviour change to create more environmentally sustainable workplaces and work styles. The research demonstrated the different understandings people have of what sustainability in the workplace should mean and whose responsibility they think it should be. The results were developed into a model of four different sustainability cultures, pragmatist, libertarian, housekeeper and campaigner, based upon people’s perception of the cost of sustainability to both company and employees. This model can be used to provide insight into the predominant sustainability culture of an organisation as well as the attitudes of individual employees.